High explosive



Patented Sept. 23, 19 24.

U'NIED STATES 1,509,362 PATENT OFFICE.

JOHN MARSHALL, OF SWARTHMORE, PENNSYLVANIA, ASSIGNOR TO E. DU PONT DE NEMOURS & COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION DELAWARE.

No Drawing.

To all whom it may concern:

Be it known that I, JOHN MARSHALL, a citizen of the United States, and a resident of Swarthmore, in the county of Delaware and State of Pennsylvania, have invented certain new and useful High Explosives, of which the following IlS a specification.

My invention relates to blasting explosives containing finely comminuted propellent powders.

By propellent powder I mean to include the several varieties of pyro powders and cordites on hand in this country as excess stores following the war. The )ropellent powders may be comminuted y any desirable type of grinding or disintegrating process.

Previous to my invention, ground propellent powders have been used in conjunction with sodium nitrate or other mineral -ni-.

trates to form blasting explosives. However, such explosives have been very dusty to manufacture, and hence dangerous to make, and have been extremely bulky and free-running.

In co-pending application Serial No. 527,488, there has been described a method of overcoming these difficulties by the addition during mixing of a relatively small percentage of liquid explosive, such as nitroglycerine.

I have now discovered that satisfactory results are also obtained by the addition to the explosive during mixing of a similar amounlt of aromatic nitro-compound liquid at the temperature of mixing, or at least capable of becoming gelatinized with the powder at this temperature. For this purpose I may preferably use such nitrobenzenoid materials as nitrobenzene, liquid dinitrotoluene, liquid .trinitrotoluene, or

nitrated solvent naphtha or mixtures of such materials.

The precentag'e of aromatic nitro-com-= pound used may vary as a rule from about 1 to 10% based on the weight of the finished explosive. A typical example of the composition of my explosive is:

Chalk 1 HIGH ExPLoswE.

Application filed April 25, 1922. Serial No. 556,420.

These proportions might be varied so as to comtain 1 to 10% aromatic nitro-compounds, 30 to 90% ground smokeless powder, and from 0.0 to sodium nitrate.

The composition may also be changed in that ground cordilte may be used in place of the ground smokeless powder, or in place of a portion of it.

In addition, other materials might be used, such as wood pulp, corn meal, flour, etc., or other materials ordinarily used in the manufacture of dynamite. In place of sodium nitrate I may use other alkali-form.- ing-metal nitrates, as, for example, potassium nitrate or barium nitrate. I may also vary the fineness of m ingredients over a wide range. the most satisfactoryresults are given when the propellant is ground so that at least 100% passes a 20 mesh screen and at least 20% passes a 100 mesh screen.

In themanufacture of this explosive I have found that it is essential to mix the materials thoroughly and for a sufficient length of time to insurejthat the gelatinization of the ground propellant with the aromatic nitro-com'pound is complete. The length of time which this gelatinization takes will depend upon the method of mixing and other factors, such as temperature, moisture content of ingredients and size of charge. For example, when working at a temperature of from about (35 to 120 1. with a mixing charge of from 600 to 1100 lbs. having a moisture content of from 0 to 2%, the aromatic nitro-compound being dinitro toluene melting at 35 0., and using a mixer of the type ordinarily used in this country for the manufacture of dynamlte, the mixing period should be not less than 15 minutes. I have found that if the materials are mixed for too short a time, for example 2 to 3 minutes, the cartridges become hard and insensitive on storage.

I have also found that whenusing more than 10% nitro-aromatic compounds, it is impossible to prevent hardening of the explosive even by prolonging the time of mixin The satisfactory results obtained with this new explosive are believed to be due to the fact that by using a relatively low percentage of aromatic nitro-compound, and mixing at the proper temperature and for the proper time, I obtain complete gelatinization of the aromatic nitro-compound I have ound however, that with the nitrocellulose, with no subsequent gelatinization after mixing.

To increase the sensitiveness of my new explosive compositions I may incorporate a small percentage of powdered aluminum, for example from about 0.3 to

I claim:

1. A blasting explosive composition comprising more than 25% of a finely comminuted propellent powder, and from about 1 to of an aromatic nitro-compound completely gelatinized with said powder.

2. A blasting explosive composition comprising more than ground smokeless powder and from about 1 to 10% of dinitrotoluene.

3. A blasting explosive composition comprising from about 'to 90% of a finely comminuted propellant powder, and an aromatic nitro-compound capable of becoming gelatinized with said powder at a temperature below 120 F., the amount of said aromatic nitro-compound being less than 10% but suflicient to substantially prevent the formation of dust during normal handling of sai dexplosive composition.

4. A blasting explosive composition comprising from about 30 to 90% of a finely comminuted propellentpowder, and an aromatic nitro-compound which is liquid at a temperature below 120 1 the amount of said aromatic nitro-compound being' less than 10% but sufficient to substantially prevent the formation of dust during normal handling of said explosive compositions.

5. A blasting explosive composition comprising more than 25% of a finely comminuted propellent powder, and from 1 to 10% of a nitrobenzenoid compound capable of becoming gelatinized with said powder at a temperature below 120 F.

6. An explosive composition vcomprising more than 25% of a finely comminuted propellent powder, from about 1 to 10% of an aromatic nitro-compound completely gelatinized with said powder, and sodium nitrate.

7. An explosive composition comprising more than 25% of a finely comminuted propellent powder, from about 1 to 10% of an aromatic nitro-compound completely gelatinized with said powder, from about 0.3 to 5% of powdered aluminum, and sodium nitrate.

In testimony whereof Iafiix my signature.

JOHN MARSHALL; 

